import { CanActivate, ExecutionContext, Injectable } from '@nestjs/common';
import { Observable } from 'rxjs';
import * as jwt from 'jsonwebtoken';

@Injectable()
export class WsJwtGuard implements CanActivate {
  canActivate(
    context: ExecutionContext,
  ): boolean | Promise<boolean> | Observable<boolean> {
    const client = context.switchToWs().getClient();
    const token = client.handshake.auth.token;
    const jwtSecret = process.env.JWT_SECRET;
    if (!jwtSecret) {
      throw new Error('JWT_SECRET environment variable is missing');
    }

    if (!token) return false;
    try {
      const decoded = jwt.verify(token, jwtSecret);
      client.handshake.auth.userId = decoded.sub;
      return true;
    } catch (err) {
      return false;
    }
  }
}